Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5005393 | Electronic key locks | Johannes M. Ewalds, Evert Nieuwkoop | 1991-04-09 |
| 4972694 | Lock with an electromechanical release mechanism | Antonius Paulus Aulbers, Johannes M. Ewalds, Paul I. d'Hond | 1990-11-27 |